# Swing the Fly Issue 2.4 Spring 2015 - Page 30

ARCHIMEDES, GALILEO GALILEI, LEONARDO DA VINCI

AND SPEY CASTING

By Bintoro

So what do these three ancient thinkers/philosophers have to do with Spey casting?

A Spey rod is a ‘lever’ and is one of the simplest tools that humans use. It involves moving a load around a pivot or fulcrum point using a force. The load is the fly line, the rod is the lever and the pivot or the fulcrum point is somewhere between the upper hand and the lower hand. Levers were first described and formulated around 260 BC by the ancient Greek mathematician Archimedes. In about 1600 AD Galileo Galilei worked out the complete dynamic theory of this simple machinery. And Leonardo Da Vinci included the ‘lever’ as one of the 6 simple machines that shaped human civilization.

There are 3 classes of lever - Class 1, Class 2 and Class 3 (see diagram 1). Never mind the Class 2 lever, we are only concerned with Class 1 and Class 3 levers and their implications in Spey casting.

Class 1 Lever - the pivot/fulcrum (upper hand) is between the effort (lower hand) and the load (fly line). In an off-center Class 1 lever as in Spey casting, the load is larger than the effort, but is moved through a smaller distance.

Class 3 Lever - the effort is between the pivot/fulcrum (lower hand) and the load. Typical upper hand dominance problem is a common problem for a beginner Spey caster or for those who have a deeply ingrained in a single hand casting muscle memory. Applying a Class 3 only lever results in an open arc rod movement and will open up the forward loop.